1. Field of the Invention
This invention generally relates to a clipless or step-in bicycle pedal. More specifically, the present invention relates to a bicycle pedal that engages a cleat secured to the sole of a bicycle shoe.
2. Background Information
In recent years, bicycle pedals have been designed for specific purposes such as for comfort, recreational biking, off-road biking, road racing, etc. One particular type of bicycle pedal, which is gaining more popularity, is the step-in or clipless pedal. A step-in or clipless pedal is releasably coupled to a cleat that is secured to the sole of a cyclist's shoe. Thus, the bottom of the cyclist's shoe is fixed to the pedal for transmitting the pedaling force from the cyclist to the pedal of the bicycle. In other words, with clipless pedals, the shoes and the pedals are in a state of constant engagement when the cleats are engaged in the cleat clamping members, so the pedaling force can be transmitted efficiently to the pedals. As a result, clipless pedals are widely employed on racing bicycles used in road racing and off-road bicycles used in mountain bike racing.
The clipless or step-in pedal has a pedal spindle that can be mounted on the crank of a bicycle, a pedal body that is rotatably supported on this pedal spindle, and a cleat engagement mechanism. In an off-road bicycle pedal, a cleat engagement mechanism is formed on both sides of the pedal body. Each cleat engagement mechanism has a pair of cleat clamping members that are fixed on one of the sides of the pedal body for engaging front and rear portions of a cleat. Road racing pedals typically only have a cleat engagement mechanism on one side of the pedal body. In either case, in this type of bicycle pedal, the rider steps onto the pedal and the cleat engagement mechanism automatically grips on to the cleat secured to the bottom of the cyclist's shoe.
More specifically, when attaching the cyclist's shoe to the clipless or step-in pedal via the cleat, the cyclist moves the shoe obliquely downwardly and forwardly relative to the pedal body such that the front end of the cleat engages a front hook or clamping member of the pedal body. Once the front end of the cleat is engaged with the front hook of the pedal body, the cyclist places the rear end of the cleat in contact with a guide portion of the rear hook or clamping member of the pedal body. In this position, the cyclist presses the shoe downwardly against the pedal to cause the rear hook or clamping member to initially pivot rearwardly against the force of a spring to move the rear hook or clamping member to a cleat releasing position. The rear end of the cleat then enters a position opposite a back face of the rear hook or clamping member. Then, the rear hook or clamping member returns under the force of a biasing member or spring so that the rear hook or clamping member engages the rear end of the cleat. This engagement fixes the cyclist's shoe to the pedal via the cleat.
When releasing the shoe from the pedal, the cyclist will typically turn the shoe about an axis perpendicular or approximately perpendicular to the tread of the pedal, using the front end of the cleat as a pivoting point. As a result of this pivoting action, the rear hook or clamping member is pivoted rearwardly against the force of the spring to a cleat releasing position to release the shoe.
When clipless or step-in pedals are used for road type bikes, the pedal is typically only provided with a single clamping assembly such that the cyclist's shoe can only be coupled to one of the two sides of the pedal. Off-road or mountain type bikes, on the other hand, usually have a pair of clamping assemblies such that the cyclist's shoe can be clamped to either side of the pedal. In either case, it is desirable to design the pedal to be as compact and lightweight as possible.
One problem with clipless or step-in pedals is that they can malfunction if dirt or mud gets into the cleat engagement mechanism. Once the cleat clamping members become dirty or clogged with mud, the cleat cannot be engaged in the cleat clamping members, and the shoe cannot be attached to the pedal. Specifically, the dirt or mud often clogs the biasing mechanism such that the clamping members may not operate properly.
In view of the above, there exists a need for a bicycle pedal which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.